Project Summary/Abstract There is a constant need in the voice clinic to make effective diagnostic, surgical, and therapeutic decisions based on coupling visual judgments of vocal fold morphology and tissue motion with auditory perceptions of voice quality. Currently, laryngologists and speech-language pathologists do not have an endoscopic imaging tool that can directly capture the three-dimensional (3D) surface motion of the vocal folds in real time as patients phonate. To address this need, Physical Sciences, Inc. (PSI), in collaboration with the Center for Laryngeal Surgery and Voice Rehabilitation at Massachusetts General Hospital, proposes to develop a novel laryngeal imaging technique that combines swept-source optical coherence tomography with videostroboscopy to provide a 3D view of the vocal folds in real time during phonation, as well as tissue subsurface morphology. A novel OCT imaging approach, called parallel OCT (POCT), will be used to enable simultaneous interrogation of multiple locations along the vocal folds. This new imaging mode eliminates motion-blur artifacts exhibited by the sequential sampling provided by conventional flying-spot OCT. These state-of-the-art OCT techniques rely on raster scanning that lacks spatial co-registration and suffers from temporal aliasing when imaging rapidly moving targets such as the vibrating vocal folds. During this effort, PSI will build a clinically viable transoral endoscope that will integrate POCT and video imaging. The proposed POCT/videostroboscopy technique will be the first attempt to develop an ultra-fast diagnostic tool that performs superior-inferior surface and subsurface depth-sampling synchronized with the clinical standard of laryngeal videostroboscopy. In Phase I, instrumental specifications will be validated on the bench using aerodynamically driven excised larynx models to simulate voice production, with subsequent in vivo clinical testing planned in Phase II. Based on experience with the Phase I prototype, a second-generation parallel OCT/videostroboscopy system will be developed in Phase II to evaluate individuals with and without voice disorders. The new technology will enable cost-effective management of patients to pinpoint problems affecting an individual's vocal mechanism and to more optimally assess the efficacy of treatment before and after surgical intervention and/or voice therapy.